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The adsorption of humic substances on three different adsorbents was investigated and adsorption isotherms were applied in this research. The three adsorbents studied include granular activated carbon (GAC), ferric oxihydroxide in its beta form (β-FeOOH) and iron-coated activated alumina (AAFS). Physical and chemical characteristics of the adsorbents were also fully investigated. Calcium was added to the HS solution in order to represent water with a hardness equivalent to water hardness typically found in London (UK). The examination of the GAC indicated a large microporous area with lower surface area associated with meso- and macropores. The AAFS and β-FeOOH did not present any microporous area. The overall surface area was high for GAC (980 m2g−1) but lower for AAFS (286 m2g−1) and β-FeOOH (360 m2g−1). The Freundlich isotherm model was fitted to all adsorbent–adsorbate systems. It was shown that GAC offered a large adsorption capacity for removal of low molecular weight humics F1 (MW 0–5 kDa) but not for substances with molecular weight larger than 10 kDa (F3). The β-FeOOH adsorption capacity was only 0.43 mg g−1, compared with 9.11 and 2.55 mg g−1on GAC and AAFS, respectively. On the contrary, F1 is not well adsorbed and only F2 (5–10 kDa) can be efficiently removed by AAFS and β-FeOOH. It was strongly suggested that precipitation/condensation occurred on the adsorbent surface.

In-line fluidic devices and mills are often used for controlling crystal size distribution during crystallization. In this work, we investigated the breakage of organic crystals in three particle breakage devices. Paracetamol was selected as a model API (active pharmaceutical ingredient). In order to focus the investigation on particle breakage, we have used paracetamol suspended in its saturated solution and eliminated possible changes in particle size because of crystallization or dissolution. Particle breakage in a wet mill (WM), which is one of the commonly used particle breakage devices, is compared with the two cavitation-based devices: one based on ultrasonic or acoustic cavitation (AC) and the other based on hydrodynamic cavitation (HC). The particle size distributions (PSD) were measured by using laser diffraction. Kapur function analysis was used to study the effect of various conditions, such as rotational speed, intensity, or pressure drop, on the specific breakage rates and breakage mechanisms. The vortex-based HC device used in this work generated more fine particles than any other technique at a similar power consumption.

In this work, two discrete formulations based on the finite volume approach for a reduced fragmentation model are developed. The important features such as mass conservation and accurate prediction of the zeroth order moments are accomplished by the modification of the selection function. The new schemes can compute the second order moment, which plays a significant role in predicting the area of the particles in real life applications, with high accuracy without taking any specific measures. A thorough convergence analysis of both schemes including Lipschitz condition and consistency is presented and exhibit second order convergence. The accuracy and efficiency of both schemes is demonstrated by applying them to the depolymerization problem which commonly arises in polymer sciences and chemical engineering. It is demonstrated that the new schemes are easy to implement, computationally efficient and able to compute the numerical results with higher precision even on a coarser grid.

Background:Human milk (HM) fortification has been recommended for the nutritional optimization of very low–birthweight infants. This study analyzed the bioactive components of HM and evaluated fortification choices that could accentuate or attenuate the concentration of such components, with special reference to human milk-derived fortifier (HMDF) offered to extremely premature infants as an exclusive human milk diet.Materials and Methods:An observational feasibility study analyzed the biochemical and immunochemical characteristics of mothers' own milk (MOM), both fresh and frozen, and pasteurized banked donor human milk (DHM), each supplemented with either HMDF or cow's milk-derived fortifier (CMDF). Gestation-specific specimens were analyzed for macronutrients, pH, total solids, antioxidant activity (AA), α-lactalbumin, lactoferrin, lysozyme, and α- and β-caseins. Data were analyzed for variance applying general linear model and Tukey's test for pairwise comparison.Results:DHM exhibited significantly lower (p< 0.05) lactoferrin and α-lactalbumin concentrations than fresh and frozen MOM. HMDF reinstated lactoferrin and α-lactalbumin and exhibited higher protein, fat, and total solids (p< 0.05) in comparison to unfortified and CMDF-supplemented specimens. HMDF had the highest (p< 0.05) AA, suggesting the potential capability of HMDF to enhance oxidative scavenging.Conclusion:DHM, compared with MOM, has reduced bioactive properties, and CMDF conferred the least additional bioactive components. Reinstatement and further enhancement of bioactivity, which has been attenuated through pasteurization of DHM, is demonstrated through HMDF supplementation. Freshly expressed MOM fortified with HMDF and given early, enterally, and exclusively (3E)appears an optimal nutritional choice for extremely premature infants.

Physisorbent metal–organic materials (MOMs) have shown benchmark performance for highly selective CO2capture from bulk and trace gas mixtures. However, gas stream moisture can be detrimental to both adsorbent performance and hydrolytic stability. One of the most effective methods to solve this issue is to transform the adsorbent surface from hydrophilic to hydrophobic. Herein, we present a facile approach for coating MOMs with organic polymers to afford improved hydrophobicity and hydrolytic stability under humid conditions. The impact of gas stream moisture on CO2capture for the composite materials was found to be negligible under both bulk and trace CO2capture conditions with significant improvements in regeneration times and energy requirements.

Water is a key solvent, fundamental to supporting life on earth. It is equally important in many industrial processes, particularly within agricultural and pharmaceutical industries, which are major drivers of the global economy. The results of water contamination by common activity in these industries is well known and EU Water Quality Directives and Associated Regulations mandate that NH 4 + concentrations in effluent streams should not exceed 0.3 mg L−1, this has put immense pressure on organisations and individuals operating in these industries. As the environmental and financial costs associated with water purification begin to mount, there is a great need for novel processes and materials (particularly renewable) to transform the industry. Current solutions have evolved from combating toxic sludge to the use of membrane technology, but it is well known that the production of these membrane technologies creates a large environmental footprint. Zeolites could provide an answer; their pore size and chemistry enable efficient removal of aqueous based cations via simple ion exchange processes. Herein, we demonstrate efficient removal of NH 4 + via both static and dynamic methodology for industrial application. Molecular modelling was used to determine the cation–framework interactions which will enable customisation and design of superior sorbents for NH 4 + capture in wastewater. [ABSTRACT FROM AUTHOR]

Catalytic decomposition of the hydrogen-rich hydrazine monohydrate (N2H4·H2O) represents a promising hydrogen storage/production technology. A rational design of advanced N2H4·H2O decomposition catalysts requires an overall consideration of intrinsic activity, number, and accessibility of active sites. We herein report the synthesis of a hierarchically nanostructured NiPt/N-doped carbon catalyst using a three-step method that can simultaneously address these issues. The chelation of metal precursors with polydopamine and thermolysis of the resulting complexes under reductive atmosphere resulted in a concurrent formation of N-doped carbon substrate and catalytically active NiPt alloy nanoparticles. Thanks to the usage of a silica nanosphere template and dopamine precursor, the N-doped carbon substrate possesses a hierarchical macroporous-mesoporous architecture. This, together with the uniform dispersion of tiny NiPt nanoparticles on the carbon substrate, offers opportunity for creating abundant and accessible active sites. Benefiting from these favorable attributes, the NiPt/N-doped carbon catalyst enables a complete and rapid hydrogen production from alkaline N2H4·H2O solution with a rate of 1602 h–1at 50 °C, which outperforms most existing catalysts for N2H4·H2O decomposition.

We reported the new biphasic composites of calcium phosphate and mesoporous silica material (CaP@MSi) in the form of powders and pellets as a potential bone drug delivery system for doxycycline hydrochloride (DOX). The CaP@MSi powders were synthesized by cationic surfactant-templating method. The effects of 10, 20, and 30% CaP content in the CaP@MSi powders on the molecular surface structure, the cytotoxicity against osteoblast cells in vitro, and the mineralization potential in simulated body fluid were investigated.The CaP@MSi characterized by the highest mineralization potential (30% CaP content) were used for DOX adsorption and pelletization process. The CaP which precipitated in the CaP@MSi composites was characterized as calcium-deficient with the Ca:P molar ratio between 1.0 and 1.2. The cytotoxicity assays demonstrated that the CaP content in MSi increases osteoblasts viability indicating the CaP@MSi (30% CaP content) as the most biocompatible. The combination of CaP and MSi was an effective strategy to improve the mineralization potential of parent material. Upon immersion in simulated body fluid, the CaP of composite converted into the bone-like apatite. The obtained pellets preserved the mineralization potential of CaP@MSi and provided the prolonged 5-day DOX release. The obtained biphasic CaP@MSi composites seem to have an application potential as bone-specific drug delivery system.

Here, we report an improved synthesis of the bulky phosphanide anion [P(SiiPr3)2]−in synthetically useful yields and its complexation to group 12 metals. The ligand is obtained as the sodium salt NaP(SiiPr3)21in a 42% isolated yield and a single step from red phosphorus and sodium. This is a significantly higher-yielding and safer preparation compared to the previously reported synthesis of this ligand, and we have thus applied 1to the synthesis of the two-coordinate complexes M[P(SiiPr3)2]2(M = Zn, Cd, Hg). These group 12 complexes are all monomeric and with nonlinear P–M–P angles in the solid state, with DFT calculations suggesting that this bending is due to the steric demands of the ligand. Multinuclear NMR spectroscopy revealed complex second-order splitting patterns due to strong PP’ coupling. This work demonstrates that the synthesis of 1is viable and provides a springboard for the synthesis of low-coordinate complexes featuring this unusual bulky ligand.

The cocrystallization of lamotrigine and valproic acid affords an ionic cocrystal with improved dissolution rate and mechanical properties. The multidrug crystal has a stoichiometry that is known to positively impact the pharmacokinetics of the parent compounds. As such, the new form is a suitable epileptic treatment. From a crystal engineering perspective, the structure is sustained by a complex multimolecular motif that includes each conformer in both the protonated and deprotonated state. Statistical and computational analysis reveals that the presence of ancillary H-bond donors in an R12(4)DD (or R22(8)DD) fashion is critical to the ionization state of the components.

Controlling polymorphism in the transition from batch to continuous crystallization represents a major obstacle for the pharmaceutical industry. This work demonstrates a novel methodology to control the polymorphism of carbamazepine (CBZ) nanoparticles, a highly polymorphic BCS class II drug, using a continuous supercritical CO2antisolvent-assisted nano spray drying (SASD) process. We show herein that when supersaturation conditions are achieved in the high-pressure SASD nozzle in the presence of anionic additives (e.g., sodium stearate, sodium dodecyl sulfate), nanoparticles of the metastable CBZ form II (using sodium stearate) or the stable CBZ form III (using sodium dodecyl sulfate) are obtained from methanol solutions, respectively. This novel methodology provides control over the final polymorphic form of CBZ obtained by (1) templating the desired polymorphic form when supercritical CO2supersaturates the CBZ-additive methanol solution in the nozzle and (2) avoiding/minimizing the occurrence of any possible polymorphic transformation by immediately spray drying the supercritical antisolvent induced suspension into a dried fine powder. These results contrast with those obtained when using nonsupersaturating conditions in the SASD nozzle (amorphous CBZ is obtained, regardless of the additive used) and when using conventional spray drying (SD) where there is no antisolvent effect in the nozzle (CBZ form IV is obtained, regardless of the additive used). The impact that the mass ratio of methanol and supercritical CO2has on the supersaturation and consequently on the polymorphic outcome of carbamazepine obtained from batch and continuous supercritical CO2antisolvent crystallization processes is also discussed.

Spent mushroom compost biochar (SMCB) was prepared by carbonization and tested for the removal of heavy metals (Zn(II), Cu(II), and Pb(II)) by adsorption. The sorption of heavy metals was evaluated by studying several factors, such as the initial solution pH, contact time, temperature, and individual and competitive adsorption. Kinetic and equilibrium studies were carried out to determine the mechanism involved during adsorption. The Weber–Morris model demonstrated the significance of intraparticle diffusion on the adsorption process. In addition, thermodynamic studies showed that the process is endothermic and favorable, with good affinity of metals to the biochar. At last, SMCB was used as the adsorbent in a continuous fixed-bed column. The breakthrough curve was obtained for each heavy metal, and Thomas and Clark models were fitted. When all three metals coexisted in solution, competitive adsorption took place in both batch and continuous systems, showing that Pb has higher affinity to SMCB than Cu and Zn.

In this study, a set of 24 experiments was designed to understand the combined effect of different process parameters, i.e. material feed rate, liquid-to-solid (L/S) ratio, screw speed, and screw configuration on the residence time distribution, granule morphology, and particle size distribution in twin screw wet granulation of microcrystalline cellulose. It was shown that residence times were longer at higher L/S and lower screw speeds. However, the most dominant effect on mean residence time had screw configuration, with longer residence times observed with increasing complexity of the screws employed. Scanning electron microscopy and laser diffraction measurements showed accordingly that the most important quality attribute affecting size of granules is L/S ratio. The relationships between input and output parameters observed for our low throughput setup generally match those concerning higher throughput granulators described in literature.

The Flory–Huggins (F–H) solubility equation has been widely used to describe the solubility of a small-molecule drug in a polymeric carrier and thus determine the design space available for formulating a stable amorphous solid dispersion. The F–H interaction parameter (χ) describes the thermodynamic properties of drug–polymer solutions and accounts for any enthalpic and entropic changes in solubility. Many studies have found that for a limited compositional range, χ varies proportionally to the inverse of the melting temperature of the drug. We explored this relationship using a highly sensitive DSC technique to detect remaining residual crystalline active pharmaceutical ingredients (APIs) following annealing of ball milled mixtures of crystalline itraconazole (ITZ) and either Soluplus or hydroxypropyl methylcellulose phthalate (HPMCP) at temperatures near the estimated solubility curve. Depending on the experimental approach taken, the measurement of drug–polymer solubility can be restricted to mixtures with a high proportion of drug, but in this study, solubility was experimentally determined for mixtures with API content as low as 10 wt %. Results suggest that the proposed linear relationship does not extend to compositions with smaller amounts of API, instead indicating that χ was both temperature- and composition-dependent for the systems studied. The feasibility of this technique to measure interactions in a ternary system containing itraconazole and both polymers was also determined; ITZ–HPMCP exhibited the most favorable values of χ, while ITZ–Soluplus and ITZ–Soluplus–HPMCP demonstrated similar interaction parameters.

A new 1:1 drug-drug cocrystal of theophylline (THP) and aspirin (ASP) was successfully prepared by liquid assisted grinding, evaporative crystallization, and slurry conversion crystallization. The obtained cocrystal was comprehensively characterized by single crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared analysis. Ternary phase diagrams were constructed for the obtained cocrystal in isopropyl alcohol at two different temperatures, i.e., 20 and 40 °C. A narrow stability region was found for the pure THP-ASP cocrystal in the phase diagram at both temperatures. By proper selection of the ratios between THP, ASP, and IPA from the stability region, THP-ASP cocrystals could be purely produced by isothermal slurry conversion in IPA. In addition, molecular modeling was deployed to provide mechanistic insights into the formation of this THP-ASP cocrystal system.

Originally discovered almost a century ago, cocrystals continue to gain interest in the modern day due to their ability to modify the physical properties of solid-state materials, particularly pharmaceuticals. Intensification of cocrystal research efforts has been accompanied by an expansion of the potential applications where cocrystals can offer a benefit. Where once solubility manipulation was seen as the primary driver for cocrystal formation, cocrystals have recently been shown to provide attractive options for taste masking, mechanical property improvement, and intellectual property generation and extension. Cocrystals are becoming a commercial reality with a number of cocrystal products currently on the market and more following in registration and clinical trial phases. Increased commercialization of cocrystals has in turn necessitated additional research on methods to make cocrystals, with particular emphasis placed on emerging technologies that can offer environmentally attractive and efficient options. Methods of producing cocrystals and of harnessing the bespoke physical property adjustment provided by cocrystals are reviewed in this article, with a particular focus on emerging trends in these areas.

The optimisation of Fe and Al oxyhydroxide materials produced using industrial grade coagulants is presented in this work. The effects of synthesis pH and post-synthesis washing procedure onto the arsenic adsorption capacity of the materials were investigated. It was shown that the materials produced at higher pH were more efficient in removing As(V), especially after cleaning procedure. The materials produced at lower pH were less efficient in removing As(V) but the higher presence of sulphate groups in the materials produced at lower pH enhanced As(III) adsorption. Most performing materials can remove up to 84.7 mg As(V) g −1 or 77.9 mg As(III) g −1 . [ABSTRACT FROM AUTHOR]

The formulation of BCS Class II drugs as amorphous solid dispersions has been shown to provide advantages with respect to improving the aqueous solubility of these compounds. While hot melt extrusion (HME) and spray drying (SD) are among the most common methods for the production of amorphous solid dispersions (ASDs), the high temperatures often required for HME can restrict the processing of thermally labile drugs, while the use of toxic organic solvents during SD can impact on end-product toxicity. In this study, we investigated the potential of supercritical fluid impregnation (SFI) using carbon dioxide as an alternative process for ASD production of a model poorly water-soluble drug, indomethacin (INM). In doing so, we produced ASDs without the use of organic solvents and at temperatures considerably lower than those required for HME. Previous studies have concentrated on the characterization of ASDs produced using HME or SFI but have not considered both processes together. Dispersions were manufactured using two different polymers, Soluplus and polyvinylpyrrolidone K15 using both SFI and HME and characterized for drug morphology, homogeneity, presence of drug–polymer interactions, glass transition temperature, amorphous stability of the drug within the formulation, and nonsink drug release to measure the ability of each formulation to create a supersaturated drug solution. Fully amorphous dispersions were successfully produced at 50% w/w drug loading using HME and 30% w/w drug loading using SFI. For both polymers, formulations containing 50% w/w INM, manufactured via SFI, contained the drug in the γ-crystalline form. Interestingly, there were lower levels of crystallinity in PVP dispersions relative to SOL. FTIR was used to probe for the presence of drug–polymer interactions within both polymer systems. For PVP systems, the nature of these interactions depended upon processing method; however, for Soluplus formulations this was not the case. The area under the dissolution curve (AUC) was used as a measure of the time during which a supersaturated concentration could be maintained, and for all systems, SFI formulations performed better than similar HME formulations.

The performance of a highly cross-linked polyethylene catalyst supported on alumina for low temperature selective catalytic reduction of NO x by unburned hydrocarbons (HCs) existing in an exhaust gas was examined at different engine conditions with the addition of exhaust-gas recirculation. The HXPE catalyst was shown to exhibit good NO x reduction activity at low temperatures (100–250°C) where the only reductant was the unburned HC, which was already present in the exhaust flow. The maximum NO x reduction of approximately 52% was achieved at a temperature of 150°C. HXPE demonstrated very good selectivity toward N2 in the majority of tested conditions (∼80%). [ABSTRACT FROM AUTHOR]

An experimental study on the adsorption of phosphate onto cost effective fine dolomite powder is presented. The effect of solution pH, solution ionic strength and adsorption isotherm were examined. The adsorption of phosphate was pH dependent and phosphate adsorption favoured acidic conditions. The adsorption was significantly influenced by solution ionic strength indicating outer-sphere complexation reactions. The experimental data further indicated that the removal of phosphate increased with increase in the ionic strength of solution. The experimental data were modelled with different isotherms: Langmuir, Freundlich and Redlich–Peterson isotherms. It was found that the Redlich–Peterson isotherm depicted the equilibrium data most accurately. The overall kinetic data fitted very well the pseudo-first-order rate model.

Abstract: Photocatlytic removal of three pharmaceutical and personal care products pollutants using novel TiO2–Coconut Shell Powder (TCNSP) composite was investigated. The photocatalytic degradation rate of PPCPs generally increased with increasing light intensity and dissolved oxygen concentration. The degradation rate decreased with increasing initial concentration of PPCPs. The PPCPs concentration decreased substantially under irradiation of UVC when used in conjunction with the TCNSP composite. A number of composite/radiation types and intensities were tested. The concentration rate decrease trend was as: UVC/TCNSP>UVA/TCNSP>UVC>UVA. Under the UVC/TCNP combination, 99% removal was achieved compared to 30% for TiO2. [Copyright &y& Elsevier]

Calcium carbonates originating from marine sources show unique pore structure and nano-architecture, offering potential in the field of hard tissue engineering. It is hypothesised that the use of naturally-sourced raw materials for the synthesis of hydroxyapatite (HA), as a component of a hard tissue constructs, enables enhanced bone remodelling due to the biomimetic physical-chemical characteristics of the HA. The aim of this study was to convert coccolith rich chalk to HA with the potential application of aiding bone tissue regeneration. This was attained by using a hydrothermal technique at an ambient pressure and low temperature 100ºC in an alkaline environment. The chalk was characterised using ICP, TGA, XRD and SEM to determine the physiochemical properties both pre-and post-synthesis. The results confirmed a high rate of conversion to HA at 93.7%. In addition the synthesised HA preserved the unique structure of the coccoliths which could be beneficial in bone repair applications.

Abstract: The machine readable encoding language XML is used in water informatics to describe resources and observational data, such as the Water Data Transfer Format (WDTF). WDTF is part of an Australian initiative, established by the Australian Bureau of Meteorology in collaboration with CSIRO, to collate water resources data from multiple data providers into a national water information system. A common way of validating XML data is by defining a schema using XML Schema Definition language (XSD) and performing validation using standard XSD tools. However, XSD validation lacks the ability to perform content validation to assert context, domain and organizational rules such as soft-typing, co-constraints, and code-list or vocabulary checking, which is required in the validation of WDTF data. In this paper, we describe a validation service for validating water resources data encoded in WDTF, which combines structural and content validation. We also describe the use of a vocabulary service with the WDTF validation service to perform code-list and vocabulary checking.

Catalyst doping has been widely employed as an effective method for improving the H-exchange kinetics of complex hydrides. However, a viable hydrogen storage material requires favorable properties on both kinetic and thermodynamic aspects to allow dehydrogenation and rehydrogenation reactions to proceed at moderate temperatures. In the present study, titanium halides (TiCl3or TiF3) were mechanically milled with LiBH4and examined with respect to their effects on the hydrogen storage properties of LiBH4. Experimental study showed that both halides are effective promoters. In particular, TiF3exhibits a superior promoting effect to its analogue, TiCl3, on the reversible dehydrogenation of LiBH4. Phase characterization and chemical state analysis results showed that both halides react with the host LiBH4, resulting in the in situ formation of the catalytically active Ti hydride. However, the two halogen anions differ substantially from each other in terms of state and function. Associated with the dissolution of LiCl into LiBH4, the Cl–anion can readily replace [BH4]−and exerts a stabilizing effect on the hexagonal phase of LiBH4. By contrast, the F–anion may partially substitute the anionic H in both LiBH4(hydrogenated state) and LiH (dehydrogenated state) lattices, resulting in a favorable modification of the hydrogen-exchange thermodynamics of LiBH4. The observed promoting effect of TiF3on the reversible dehydrogenation of LiBH4should be understood from the combined effects of functional cation and anion. In this regard, TiF3provides a prototype catalyst that can simultaneously modify the H-exchange kinetics and thermodynamics of complex hydrides.

Two new three‐dimensional ScIIImetal–organic frameworks {[Sc3O(L1)3(H2O)3]⋅Cl0.5(OH)0.5(DMF)4(H2O)3}∞(1) (H2L1=1,4‐benzene‐dicarboxylic acid) and {[Sc3O(L2)2(H2O)3](OH)(H2O)5(DMF)}∞(2) (H3L2=1,3,5‐tris(4‐carboxyphenyl)benzene) have been synthesised and characterised. The structures of both 1and 2incorporate the trinuclear trigonal planar [Sc3(O)(O2CR)6] building block featuring three ScIIIcentres joined by a central μ3‐O2−donor. Each ScIIIcentre is further bound by four oxygen donors from four different bridging carboxylate anions, and a molecule of water located transto the μ3‐O2−donor completes the six coordination at the metal centre. Frameworks 1and 2show high thermal stability with retention of crystallinity up to 350 °C. The desolvated materials 1 aand 2 a, in which the solvent has been removed from the pores but with water or hydroxide remaining coordinated to ScIII, show BET surface areas based upon N2uptake of 634 and 1233 m2g−1, respectively, and pore volumes calculated from the maximum N2adsorption of 0.25 cm3g−1and 0.62 cm3g−1, respectively. At 20 bar and 78 K, the H2isotherms for desolvated 1 aand 2 aconfirm 2.48 and 1.99 wt % total H2uptake, respectively. The isosteric heats of adsorption were estimated to be 5.25 and 2.59 kJ mol−1at zero surface coverage for 1 aand 2 a, respectively. Treatment of 2with acetone followed by thermal desolvation in vacuo generated free metal coordination sites in a new material 2 b. Framework 2 bshows an enhanced BET surface area of 1511 m2g−1and a pore volume of 0.76 cm3g−1, with improved H2uptake capacity and a higher heat of H2adsorption. At 20 bar, H2capacity increases from 1.99 wt % in 2 ato 2.64 wt % for 2 b, and the H2adsorption enthalpy rises markedly from 2.59 to 6.90 kJ mol−1.

This study investigated methyl methacrylate – polymethyl methacrylate powder bed interactions through droplet analyses, using model fluids and commercially available bone cement. The effects of storage temperature of liquid monomer and powder packing configuration on drop penetration time were investigated. Methyl methacrylate showed much more rapid imbibition than caprolactone due to decrease in both contact angle and fluid viscosity. Drop penetration of caprolactone through polymethyl methacrylate increased with decrease in bed macro-voids and increase in bulk density as predicted by the modified constant drawing area penetration model and confirmed by drop penetration images. Linear relationships were found between droplet mass and drawing area with imbibition time. Further experiments showed gravimetric analysis of the polymerised methyl methacrylate – polymethyl methacrylate matrix under various storage temperatures correlated with Reynolds number and Washburn analyses. These observations have direct implications for the design of mixing and delivery systems for acrylic bone cements used in orthopaedic surgery.

We investigate high-modulus degradable materials intended to replace metals in biomedical applications. These are typically composites comprising a polylactide (PLA) matrix reinforced with phosphate glass fibres, which provide reinforcement similar to E-glass but are entirely degradable in water to produce, principally, calcium phosphate. We have made composites using a variety of fibre architectures, from non-woven random mats to unidirectional fibre tapes. Flexural properties in the region of 30 GPa modulus and 350 MPa strength have been achieved — directly comparable to quoted values for human cortical bone. In collaboration with other groups we have begun to consider the development of foamed systems with structures mimicking cancellous bone and this has shown significant promise. The fibres in these foamed structures provide improved creep resistance and reinforcement of the pore walls. To date the materials have exhibited excellent cellular responses in vitroand further studies are due to include consideration of the surface character of the materials and the influence of this on cell interaction, both with the composites and the glass fibres themselves, which show promise as a standalone porous scaffold.